Bump ajv

Bumps [ajv](https://github.com/ajv-validator/ajv) from 6.10.0 to 6.12.3.
- [Release notes](https://github.com/ajv-validator/ajv/releases)
- [Commits](ajv-validator/ajv@v6.10.0...v6.12.3)

---
updated-dependencies:
- dependency-name: ajv
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

service-mesh/istio/sample/istio-plural-course/06/demos/src/rng/numbers-web/ClientApp/package-lock.json

@@ -17,7 +17,7 @@
     "rimraf": "^2.6.2"
   },
   "devDependencies": {
-    "ajv": "^6.9.1",
+    "ajv": "^6.12.3",
     "cross-env": "^5.2.0",
     "eslint": "^5.12.0",
     "eslint-config-react-app": "^4.0.1",